Color photographic element containing speed improving compound in combination with reflecting material

Abstract

Disclosed is a color silver halide photographic element comprising a support bearing: (1) a light sensitive silver halide emulsion layer; (2) a nitrogen heterocycle with a minimum of three heteroatoms that does not react with oxidized developer, does not contain free thiol substituents, and has a ClogP sufficient to increase the photographic speed of said element compared to the same element without the compound, said heterocycle compound located either in said light sensitive layer or in a layer adjacent to it; and (3) a light reflecting silver halide material; provided that the heterocycle compound and the light reflecting material are located either (a) in different layers of the element located close enough to each other so that a super-additive speed increase is realized or (b) in the same light sensitive layer. The invention provides improved light sensitivity.

What is claimed is:  
     
       1. A color silver halide photographic element comprising a support bearing: 
       (1) a light sensitive silver halide emulsion layer;  
       (2) a nitrogen heterocycle with a minimum of three heteroatoms that does not react with oxidized developer, does not contain free thiol substituents, and has a ClogP sufficient to increase the photographic speed of said element compared to the same element without the compound, said heterocycle compound located either in said light sensitive layer or in a layer adjacent to it; and  
       (3) a non-light sensitive light reflecting silver halide material;  
       provided that the heterocycle compound and the light reflecting material are located either (a) in different layers of the element located close enough to each other so that a super-additive speed increase is realized or (b) in the same light sensitive layer.  
     
     
       2. The element of  claim 1  wherein the light reflecting material is present in a non-light sensitive layer. 
     
     
       3. The element of  claim 2  wherein the non-light sensitive layer is located closer to the support than the light sensitive layer. 
     
     
       4. The element of  claim 3  wherein said light sensitive layer is the most light sensitive of a plurality of layers all predominantly sensitive to the same color light. 
     
     
       5. The element of  claim 4  wherein the heterocycle compound is present in the light sensitive layer. 
     
     
       6. The element of  claim 4  wherein the heterocycle compound is present in a non-light sensitive layer farther from the support than the light sensitive layer. 
     
     
       7. The element of  claim 1  wherein the light sensitive silver halide emulsion layer is primarily blue light sensitive and the light reflecting material is an undyed tabular or a small 3-D silver bromide or iodobromide emulsion with 10 mole % or less iodide. 
     
     
       8. The element of  claim 7  wherein the light reflecting material is a tabular emulsion with a thickness from 0.10 to 0.15 μm and an aspect ratio greater than 15 or a 3-D emulsion with an ECD of from 0.1 to 0.4 μm. 
     
     
       9. The element of  claim 1  wherein said light sensitive silver halide emulsion layer is green light sensitive and the light reflecting material is an undyed tabular or a 3-D silver bromide or iodobromide emulsion with 10 mole % or less iodide. 
     
     
       10. The element of  claim 9  wherein the light reflecting material is a tabular emulsion with a thickness from 0.06 to 0.11 μm and an aspect ratio greater than 17 or a small 3-D emulsion with an ECD of from 0.10 to 0.50 μm. 
     
     
       11. The element of  claim 1  wherein the light sensitive silver halide emulsion layer is red light sensitive and the light reflecting material is an undyed tabular or a small 3-D silver bromide or iodobromide emulsion with 10 mole % or less iodide. 
     
     
       12. The element of  claim 11  wherein the light reflecting material is a tabular emulsion with a thickness from 0.03 to 0.12 μm and an aspect ratio greater than 5 or a small 3-D emulsion with an ECD of from 0.10 to 0.80 μm. 
     
     
       13. The element of  claim 1  wherein the heterocycle compound is a tetraazaindene with a ClogP of at least 6.2. 
     
     
       14. The photographic element of  claim 4  wherein the heterocycle compound is a tetraazaindene with a ClogP of at least 6.2. 
     
     
       15. The element of  claim 1  wherein the heterocycle compound is a 1,3,4,6-tetraazaindene (purine) with a ClogP of at least 6.2. 
     
     
       16. The element of  claim 15  wherein the 1,3,4,6-tetraazaindene is represented by the Formula I:                    
       wherein R 1  and R 2  are each independently hydrogen or an alkyl, aryl, alkoxy, aryloxy, alkylthio, arylthio, sulfoxyl, sulfonyl, sulfamoyl, fluoro, chloro, bromo, iodo, cyano, nitro, —O—CO—, —O—SO 2 —, heterocyclic, carbonyl, amino, carbonamido, or sulfonamido group and R 3  is an alkyl, aryl, alkoxy, aryloxy, alkylthio, arylthio, secondary or tertiary amino, carbonamido, sulfonyl or sulfonamido group. 
     
     
       17. The element of  claim 16  wherein R 3  is an alkoxy or alkylthio group. 
     
     
       18. The element of  claim 4  wherein the heterocycle compound is a 1,3,4,6-tetraazaindene (purine) with a ClogP of at least 6.2. 
     
     
       19. The element of  claim 1  wherein the heterocycle compound is a benzotriazole with a ClogP of at least 7.8. 
     
     
       20. The element of  claim 19  wherein the benzotriazole is represented by Formula V:                    
       wherein R 8 , R 9 , R 10  and R 11  each individually represents hydrogen or an alkyl, aryl, alkoxy or aryloxy, alkylthio or arylthio, sulfoxyl, sulfonyl, sulfamoyl, fluoro, chloro, bromo, iodo, cyano, nitro, —O—CO—, —O—SO 2 —, heterocyclic, carbonyl, carbonamido, sulfonamido, or amino group. 
     
     
       21. The element of  claim 20  wherein R 8  and R 11  are hydrogen and where R 9  is a carboxylate ester, a carbamoyl, a carbonamido, a sulfonamido, an alkoxy, or aryloxy group. 
     
     
       22. The element of  claim 4  wherein the heterocycle compound is a benzotriazole with ClogP of at least 7.8. 
     
     
       23. The element of  claim 1  wherein the heterocycle compound is a triazole with ClogP of at least 8.75. 
     
     
       24. The element of  claim 23  wherein the triazole is a 1,2,3-triazole represented by Formula VI:                    
       wherein R 12  is hydrogen, or an alkyl or aryl group, and R 13  is an alkylthio, arylthio, carboxylate ester or substituted alkyl group. 
     
     
       25. The element of  claim 23  wherein the triazole is a 1,2,4-triazole represented by Formula VII:                    
       wherein R 12  is hydrogen, or an alkyl, or aryl group and R 13  is an alkylthio, arylthio, carboxylate ester, or alkyl group. 
     
     
       26. The element of  claim 4  wherein the heterocycle compound is a triazole with ClogP of at least 8.75. 
     
     
       27. The element of  claim 1  wherein the heterocycle compound is a tetrazole with a ClogP of at least 6.5. 
     
     
       28. The element of  claim 27  wherein the tetrazole is represented by Formula IX:                    
       wherein R 17  is hydrogen and R 16  is an alkyl, aryl, amino, alkoxy, aryloxy, heterocyclic, alkylthio, or arylthio group. 
     
     
       29. The element of  claim 4  wherein the heterocycle compound is a tetrazole with a ClogP of at least 6.5. 
     
     
       30. The element of  claim 1  wherein the heterocycle compound is selected from an oxa- or thia-diazole with a ClogP of at least 7.6. 
     
     
       31. The element of  claim 30  wherein the heterocycle is an oxadiazole represented by Formula VIII:                    
       wherein X is oxygen; R 14  is an alkylthio or arylthio group and R 15  is an alkyl, aryl, alkylthio, arylthio, or amino group. 
     
     
       32. The element of  claim 30  wherein the heterocycle is a thiadiazole represented by Formula VIII:                    
       wherein X is sulfur; R 14  is an alkylthio or arylthio group and R 15  is an alkyl, aryl, alkylthio, arylthio, or amino group. 
     
     
       33. The element of  claim 4  wherein the heterocycle compound is selected from an oxa- or thia-diazole with a ClogP of at least 7.6. 
     
     
       34. The element of  claim 1  wherein the element is an origination material for capturing an original image. 
     
     
       35. The element of  claim 1  in which the heterocycle compound is present in an amount sufficient to increase the speed of a neutral exposure by at least 0.1 of a stop compared to the same element without the compound. 
     
     
       36. The element of  claim 5  wherein the ratio of number of millimoles of the heterocyclic compound to the number of moles of silver in the same layer is greater than 1.0. 
     
     
       37. The element of  claim 6  in which the heterocycle compound is present at a laydown of 3.0×10 −5  mol/m 2  or greater. 
     
     
       38. The element of  claim 1  wherein the nitrogen heterocycle compound is selected from the group consisting of:                    
     
     
       39. The element of  claim 1  which additionally contains a compound that imagewise releases an electron transfer agent upon development. 
     
     
       40. The element of  claim 39  wherein the electron transfer agent releasing compound is represented by the formula: 
       
         
           CAR—(L) n —ETA  
         
       
       wherein: 
       CAR is a carrier moiety which is capable of releasing —(L)n—ETA upon reaction with oxidized developing agent;  
       L is a divalent linking group;  
       n is 0, 1 or 2; and  
       ETA is a releasable 1-aryl-3-pyrazolidinone electron transfer agent having a ClogP of at least 2.40 bonded to L or CAR through either the nitrogen atom in the 2-position or the oxygen attached to the 3-position of the pyrazolidinone ring.  
     
     
       41. The element of  claim 40  wherein L comprises a quinone methide, pyrazolonemethide or intramolecular nucleophilic displacement linking group or includes an —O—C(═O)—, O—C(═S)—, O—C(═NR 8 )— or O—C(═NSO 2 R 10 )— group as the sole link between CAR and ETA or in addition to another linking group, wherein R 8  and R 10  are H or substituents. 
     
     
       42. The element of  claim 1  wherein the equivalent circular diameter (ECD) of the average light reflecting material is less than ½ the size of the largest imaging silver halide present in the light sensitive layer. 
     
     
       43. The element of  claim 42  wherein the light sensitive silver halide emulsion layer comprises a silver iodobromide emulsion with an ECD of 2.5 or greater. 
     
     
       44. The element of  claim 42  wherein the ECD of the average light reflecting silver halide is less than ¼ the size of the largest imaging silver halide present in the light sensitive layer.